Control apparatus



YMay 27, 1941.

E c. RANEYY CONTROL APPARATUS Filed lay 19, 1937 4 Sheets-Sheet 1- N@AIN l S @S QQ P2 SQ JIT *Q i. H U g l w1 A n.0, om. ,l n* l t. -l ox wl N 1 5Nl n, QQ Q w t I. /n W QQ INVENTOR ATTORNEY May 2 7, 1941.

E. C. RANEY CONTROL APPARATUS Filed May 19, 1937 4 Sheets-Sheet 2 m. NWN. mi QQ su S NQ @HQ QQ R H o m H". 9v E uw m m 1 l, .5w 2, W,w/ om p IJJI OW *mi `."Q/ QM. ISB o .mk n* a M o, l mm. ww 1.9 Q QW Qw\\ Img k P.w ING. EN \.3 A E a m /w d/(Nu, NQ N n wv ATTORNEY May 27, 1941. E. c.RANEY CONTROL APPARATUS Filed May 19, 1937 4 Sheets-Sheet 3 May 27,1941. E c. RANEY v2,243,166

CONTROL APPARATUS Filed May 19, 1937 4 Sheets-Sheet 4 jj INVENToR BY Y2/Patented May 27, 1941 CONTROL APPARATUS Estel C. Raney, Columbus, Ohio,assignor to Ranco Incorporated, Columbus, Ohio, a corporation of OhioApplication May 19, 1937, Serial No. 143,558

5 Claims. (Cl. 175-320) My present invention relates to control Systemsand apparatus for use in such systems, and more particularly electricalcontrol systems and apparatus for controlling fuel burning devices.

One of the objects of my present invention is to provide a controlsystem which includes an electrically operated safety mechanism which isenergized continuously during the operating period of the fuel burningdevice and which is capable of rendering the system inoperative in theevent of failure of combustion, the control system also including adevice, which is responsive to combustion conditions, for preventing theoperation of the safety mechanism and thereby prevent stopping of thefuel burning device, when the fuel burning device operates in a normalmanner.

In carrying' out the above object, it is a further object of myinvention to provide the system with a heat dissipator which isassociated with the thermally operated safety mechanism, upon theestablishment of combustion, for modifying the temperature thereof tobelow the operating temperature of the mechanism, thus preventingoperation of the safety mechanism during normal operating periods of thefuel'burner.

A further object of my invention is to provide the system with a currentcompensator for varying the energizing current for the said thermallyoperated safety mechanism inversely with respect to variation of theambient temperature, thus causing the mechanism to always operate withina definite time period regardless of changes in ambient temperature.

It is a still further object of my invention to provide a constantcurrent transformer for the system, wherein compensating devices areprovided, for varying the current output therefrom to any desired value,and for varying the current output with respect to the ambienttemperature.

' Another object of my invention is to providev a thermally operatedcircuit breaker that is constantly heated during the operating periodsof the device to be controlled and which includes a heat dissipatorthat` is associated with the circuit breaker during normal operatingperiods of the device for modifying the temperature of the circuitbreaker and thereby preventing the same from operating, the heatdissipator being operable to be moved out of engagement with the-circuit breaker and allowing the same to operate in the event that theoperation of the device, to be'controlled, is abnormal.

Other and further objects and advantages will be apparent from thefollowing description, reference being hady to the accompanying drawingswithin a preferred form of embodiment of the present invention isclearly shown.

In the drawings:

Fig. l is a side elevational view of the assembled control apparatus;

Fig. 2 is a view of the underside of the apparatus;

Fig. 3 is a side elevational view of the appa ratus taken on theopposite side to that shown in Fig. 1;

Fig. 4 is a front elevational view of the apparatus:

Fig. 5 is a sectional view on an enlarged scale of the heat dissipatoror radiator in contacting position, the section being taken on line 5-5of Fig. 1;

Fig. 6 is a sectional view on an enlarged scale of the spring clutcharrangement used to provide a slip connection between the bimetallicelement and the actuating member of the combustion control;

Fig. 7 is a sectional view on an enlarged scale taken on line 1-1 ofFig. 1;

Fig. 8 is a fragmentary view of the transformer showing the mechanismutilized to operate the motor switch;

Fig. 9 is partial sectional view on an enlarged scale of the heatdissipator in the non-contacting position;

Fig. 10 is an enlarged view of the counterbalance spring and adjustmenttherefor, as used with the floating secondary of the transformer, and,

Fig. 11 is a schematic wiring diagram-showing the electrical connectionsused in the control system.

The construction of the apparatus may be best understood by referring tothe drawings, wherein an assembled unit is shown in Fig. 1. A constantcurrent transformer, generally indicated at 20, includes a core 22having an arcuate section. The core 22 includes an internal slot 2| ofarcuate shape. 'Ihe core 22 is preferably laminated, and is made of anysuitable number of plates 24. The plates 24 are clamped between two sideor end 'plates 26 and 28 by screws 3l and 32. The end plates 26 and 28are provided with extending portions or legs 3| and 36 respectively andare bent outwardly and at right angles to the surface of the plates. Thelegs 3l and 36 are used as mounting brackets for attaching the plates 2|and 28 and the appended core 22 to a dielectric plate 38, which may betermed the base plate. The base 38 is attached to the plates 26 and 28by screws 40 and 42.

A primary winding 48 is wound around the lower portion of core 22 and itwill be noted that the core is out away as at 50 to allow the primarycore 48 toA extend inwardly without contacting the opposite side of thecore. A secondary coil 52, or as it may be termed, a movable armature,is wound on a spool 54. The spool 54 is disposed around that section ofthe core which is formed by the arcuate shaped slot 2|. The bore of thespool 54 is suciently large to after passing through the base 38,engages a Y spring mounting 86 of a movable contact 88. The

allow the spool to slide easily over the arcuate v core section withoutengaging the core. The spool 54 and secondary coil 52 are supported by aU shaped lever 56 which is fastened to the spool 54 as by clinching. Themounting lever 56 is pivotally carried by a rod 58, which rod isjournalled in two outwardly extending ears 60, formed integrally withthe end plates 26 and 28. Thus the secondary coil is pivotally mountedand is free to move when energized, in an arcuate path over the core2'2, the bearing point for the rod 58 being at the center of a circle ofwhich the y curved outer portion of the core 22 is a quadrant.

spring 86 is mounted on a lug 90 secured to the base 38, which lug isused as a terminal connection. The spring mounting 88 is normally biasedso that the movable contact 88 engages a. iixed contact 92 which is alsocarried b y the base 38. When the secondary coil 52 is not energized, asshown in Fig. 1, the lever 82 is extended and forces the movable contact88 out of engagement with the fixed contact 82, to break the circuittherethrough. It will be noted that the counterbalance hereinbeforedescribed', must be adjusted so that the weight of the secondary coil52, acting through lever 82, will separate the contacts 88 and 92 whenthe secondary 52 is deenerbiased to counterbalance, or partlycounterbalance the weight of .the coil 52. Plate 64 is su-bstantiallycircular in shape and is rotatably carried by the rod 58 and abuts thelever arm 56. A screw 6 6 is threadedl into the lever 56 and is disposedso that the screwhead overlaps the plate 64. Thus when the screw 66 istightened, the

platel64 is clamped in place between the screw` p sage of air betweenthe plates.

form and one end thereof is held' in a slot 10 in the rod 5s. fastenedto an adjustable pointer 12. The pointer 12 is associated with aradially shaped ear 14 that may be formed integrally with the end plate26. The ear 14 is slotted arcuately at 16, which slot is`disposed toreceive a screw 18 that also passes through the pointer 12. A nut 80,disposed on the opposite side of the ear 14, is'utilized to lock thescrew and adjustable pointer 12 in any desired position against the ear14. Thus the tension of the bimetailc spiral 68 may be varied withinreasonable limits. The bimetallic spiral 88 is used as an ambienttemperature compensator which will be explained in detail.

Referring to Fig. 8, a fragmentary. view of the core 22, is shown inwhich a lever or arm 82 `is pivoted at 84 on the lever 56. The arm 82passes through an aperture 85 in the base 88. The aperture 85-issumciently large to eliminate any binding effect between the base 88 andthe lever l2. The lever 82 is insulated from the mounting lever 56, orit may be fabricated from some suitable insulating material. The freeend of the lever 82.

The other end of the spiral 68 is gized. When the secondary coil 52 isenergized, the lever 82 is retracted', and thecontacts 88 and 92 closedue to the action of spring 86. It should be noted that when thetransformer is in operating condition, that the secondary coil 52 movesthe lever 82 out of Contact with the switching mechanism, which relievesthe lever 82 and the secondary coil 52 from any pressure due to contactthrough the lever, thus reducing friction and allowing the secondarycoil to assume a substantially floating condition which affords accuratecurrent compensation.

The screws 30, which are usedto clamp the core between the two endplates,are of sufficient length to pass through the end plates 26 and 28and engage a threaded mounting .plate 44. The end plate 28 is spacedfrom the mounting plate 44 by tubular spacers 46 that are passed overthe screws 30. The spacers 46 effectively space, not only thetransformer 20 but also all the mechanism which is depended from theattached base plate 38.

The mounting plate 44 is likewise spaced from a similarly shaped vplate94 by screws 96 and associated tubular spacers 98. This arrangementmaintains the plates at a definite position with respect to each other.-The plates 44 and 94 are each provided with a flange around the edgesthereof, to strengthen the plates and prevent buckling. The open spacebetween the two plates 44 and 94 is provided to allow for the free pas-This effectively insulates the working mechanism of apparatus from theheat of combustion, When the control is mounted on a stack or otherwiseassociated with a furnace or the like.

A plate |02 is held between the plates 44l and 94 at the lower endsthereof by lugs |04, which are formed integrally with the plate |02. Ascrew 06, which passes through an elongated hole |08 in the plate |02,is threaded into the plate 94. The plate |02 may be termed a conduitplate as it is provided with two holes ||0 and ||2 which are of theproper size to receive BX connectors or other types of cable couplings.The plate |02 is easily removed from.' the mounting plate by looseningtire screw |06 and sliding the plate 94 forwardly to disengage thc lugs|04 from the mounting plate 44.

A tube I|4 is attached to the upper end f the outer plate 44, as byclinching and extends inwardly from the plate 44 and through plate 94 toprovide a support for the thermostat mechanism of a combustion control.Referring toFig. 6, it will be noted that the plate 44 hasvbeen'depressed to form a conical indentation or bearing as at ||6. Ears orprojections ||5 formed integrally on the end of the tube I |4 are passedthrough the plate 44 around the base of the bearing I|8 and are clinchedon the opposite side of the plate 44. The other end of the tube ||4carries an extension ||8 which is spot welded, or otherwise suitablyattached to the tube. The extension ||8 forms a rigid support for oneend of a helical thermostatic member which is formed from a bimetallicstrip. The thermostatic member |20 is connected to the extension ||8 bya screw |22. The outer end of the helical member |20 is attached by ascrew |24 to one end of a rod |26, which is flattened at |21 providing asuitable at bearing surface for the bimetallic member |20. The other endof the rod |26 passes through the bearing ||6 in plate 44.

When the thermostatic mletal |20 is heated, it expands and causesrotation of the attached rod |26, which movement is utilized to operateother mechanism included in the apparatus.

The inner `or other end of the rod |26 is threaded to receive a nut |28which secures a compression spring |30 and a lever |32 in place againsta Washer |34 which washer is flxedly attached to the rod |26. 'Ihisspring coupled assembly of lever |32, spring |30 and washer |34 forms afriction clutch arrangement which, due to the friction between the4lever |32 and washer |34, as caused by compression spring |30, causesthe lever |32 to rotate with the rod |26 and washer |34 until the lever|32 reaches its definite limit of movement as determined by itsassociated mechanism. At this point, further rotation of the rod |26causes slipping to occur between the lever |32 and washer |34 whichslipping permits the rod |26 to rotate as much as required withoutplacing either the lever |32 or bim'etallic member |20 under anyundesirable strain. The same operation is fullled in either direction ofrotation of the rod |26.

An outwardly extending ear |3| is formed on lever |32, which ear |3|extends through an elongated hole |42 in lever |40. The lever |40includes an outwardly pressed ear |44 which ear provides a connectionfor one end of a spring |46. The opposite end of spring |46 is connectedto the ear |3| of the lever |32. The spring |46 maintains the levers |32andv |40 in close relation at al1 times. Thus the spring |46 provides aresilient connection'between lever |40 and lever |32 that not only iswithout any end play but is also without the attendant friction thataccom.- panics a tight" bearing engagement. It should also be noted thatlever is constantly being drawn upwardly by this resilient connectionduring periods when the rod |26 is rotated due to heat on the bimetal|20. 'Ihe lower end of lever |40 is hinged at |48 to an L shapedlever.|50,

which lever |50 is hinged by a pin |54 to an extension |56, that isfixedly mounted to the base plate 38. An enlarged view of the hingedconnection between levers |40 and |50 is shown in Fig, 9.

Fig. 9 shows a radiator |60 in its displaced position as occasioned bythe mlovement of the hinged assembly of levers |32, |40 and |50. Theradiator comprises a lhollow central core portion |62 thatc-arries aplurality of heat conducting fins |64. The assembly |60 is preferablymade of brass, copper, aluminum or some other material that hasdesirable heat conducting characteristics. In the preferred form theupper closed end of the hollow core |62 is provided with a. hardenedsteel bearing |66 to resist wear from contact with the pointed bearingend of a pin |68. The pointed upper end of pin |68 bears at the apex ofthe steel bearing |66 which assures that the radiator assembly |60 isonly carried by a point, and therefore may be considered to be floatingon the pin |68. It will be noted that angularity of the point of the pin|68 is much less than the angular-ity of the conical bearing |66, whichallows free movement of the radiator |60. The lower endof the pin |68 isriveted to an insulating strip |10, which strip |10 is attached to thelever |50 as by rivets |12.

The upper end of the core |62 of the radiator |60 terminates in asubstantially fiat surface |16 which surface provides a` largeconducting surface for contacting a like fiat surface |18 on a housingdisposed around a heating coil |82. A ratchet |84, preferably fabricatedfrom insulating material, with a brass sleeve bearing |86 pressed inplace, is slipped over the housing |80 and the sleeve |86 is soldered tothe housing |80. In this manner the ratchet |84 is not rotatable on theheater housing |80 except when the solder is melted.

When the radiator |60 is in contact with the housing surface |18, asshown in Fig. 5, the radiator |60 dissipates suiiicient heat, generatedin the heating coil |82, to prevent the fusing of the solder. When theradiator is in the position shown in Fig. 9, the radiator is not in suchintimate conducting contact with the housing surface |18 and thereforedissipates less heat, if any, and, if the heating element |82 isenergized for too long a period, the solder will be fused. 'Ihus theaction of the combustion control through the bimetallic member |20 andassociated levers can displace the radiator |60 so that when thecombustion chamber is hot, due to ignition of the fuel, the radiator |60is in contact with the heater housing4 |80 to prevent the fusing of thesolder and, when the combustion chamber is cold, the radiator |60 is outof contact with the housing |80 and the heater |82, if energized for toolong a. period, will fuse the solder. The floating bearing of radiator|60 on pin |68 provides for substantially perfect contact between thesurfaces |16 and |18 to assure the maximum conductive effect ybetweenthe two surfaces.

The insulated ratchet |84 provides a bearing point for one end of aspring contact member |90, which is mounted at its opposite end to a lug|92 that is clinched to the base 38. The spring member carries a movablecontact point |94. A second spring member |96 attached to another lug|98, which is clinched to the base 38, carries a contact 200. Both ofthe spring members |90 and |96 are biased to spring toward the front ofthe apparatus and to separate the contacts since the member |90 willspring out further than the member |96. When contacts |94 and 200 are inengagement, the free end of member |90 engages one of the teeth of theratchet |84 to maintain the member |90 in a set or closed contactposition. The engagement between member |90 and ratchet |84 will bemaintained unless the soldered mounting of the ratchet |84 fuses, atwhich instant the ratchet will ,rotate counter-clockwise due to theconjoint tension of the spring contact members |90 and |96 on member|90, which in their normal biased position are always tending to rotatethe ratchet |84 to allow the contacts to separate. As soon as theratchet revolves the member |90 is disengaged and springs away frommember |96 to separate the contacts |94 and 200. After the solder hasre-hardened and ratchet |84 is again fixed in position on the heaterhousing |80, the members |90 and |96 may be reset so that contacts |94and 200 again engage by merely pressing a reset pin 202 inwardly. 'I'hereset button or pin 202 is journalled in an elongated bearing 204 whichbearing is spun over on the support or hinge member |52. The inner endof the reset pin 202 is of a smaller diameter as at 200 and passesthrough a slot 208 in the spring member |90, to assure alignment of thepin 202 with the member |90. The`reset pin 202 has a circular lockspring 2|0 snapped into a groove in the pin which spring 2|0 forms anenlarged diameter to prevent the pin 202 from being displaced from itselongated bearing 204. I'hus when the pin 202 is pressed to its maximuminward position, the contacts |94 and 200 on spring members |90 and |96engage to complete a circuit.

An adjustable secondary air shutter |35 is provided 'and is disposed onthe tube ||4. The shutter or adjustment |36 is spring fitted on the tubeand is placed on the tube ||4 between plates 44 and 94 so that it isaccessible for adjustment. The tube ||4 is provided with an air opening|38 as shown in Fig. 7. Thus it is apparent that the shutter |36 may berotated so as to vary the area of the hole |38 as desired. This allowsany desired quantity of relatively cool air from the room to circulatethrough the helix |20, to cool the same, which provides for more rapidoperation of the control after the burner has been extinguished.

Fig. 11 shows a schematic wiring diagram of the system. Power issupplied by lines 2|0 and 2|2, current passes from the wire 210, whichis connected to contact 200, to contact |94, wire 2|4, to one side ofthe transformer primary coil 48. A branch of this circuit also goesthrough wire 2|6 to contact 92, contact 88, member 86, lwire 220 to oneside of the motor 222 which operates the blower. The other side of theline, namely wire 2| 2, is connected directly to the motor 22. A branchof this circuit traverses wire 224 to the primary 48 to the transformer.'Ihus it will be noted that the primary 48 of the transformer isconstantly energized. An ignition device 223 (shown in part) isconnected in parallel with the motor 222 by wires 22| and 2'25. It willbe noted that the ignition device 223 is energized simultaneously withthe motor 222.

The secondary 52 of the transformer 20 is connected by wire 226 to aroom thermostat 228 which is connected by wire 230 to one terminal ofthe heater |82. The other heater terminal is connected to the secondary52 by wire 232. Therefore the secondary circuit is complete through thethermostat 228 and heater coil |82.

The operation of the device may be explained as follows: the primary 48of the transformer is constantly energized so that the entire system isoperatively responsive to the opening or closing of the secondarycircuit. 'I'hus when the room thermostat 228, due to a demand for heatin the enclosure being heated, closes the secondary circuit, an induced'current is caused to flow through the secondary winding 52, whichcauses the secondary 52 to be repulsed from the primary 48. This causesthe secondary 52 to move about its axis 58. This movement causes thelever 82 which is associated with the secondary 52to be drawn away fromthe contact member 86 of the motor switch, allowing contacts 88 and 92to close, which energizes the motor 222 and ignition device 223.` 'I'hemotor VThis passage of current causes the heater |82 to radiate heat,that is absorbed by the heater housing |80. If the heat output of theheater is not modified within a predetermined period the solderedmounting of the ratchet |84 will become suiiiciently heated to allow theratchet to rotate to trip the safety switch and separate contacts |94and 200. The breaking of the circuit through these contacts not onlystops the motor but also deenergizes the primary 48 of the transformer20. Thus if a fuel shortage, fuel failure due to plugged supply pipes,broken ignition system, or any other abnormal condition occurs, thesystem is quickly deenergized. When the fuel ignites properly and theoperation is normal, the bimetal thermostat |20 of the combustioncontrol causes its associated levers |32, |40 and |50 to associate theradiator, or heat dissipator |60 with the heater housing |80. Theradiator |60 modifies the temperature of the heater housing byconducting heat away from the housing |80 and radiating the heat thusobtained to the surrounding atmosphere. In this manner the heater |82does not supply sufficient heat to fuse the solder when the radiator|60- is in contact with the heater housing |80. the effect of the heater|82 whenever it is associated with the heater housing |80' to preventthe operation of the safety switch.

Another feature of my invention is the provision of current and ambienttemperature compensators in the secondary coil 52 of the transformer 20.The transformer 20 is so designed as to produce a substantially constantcurrent output at all times. Thus when the voltage of the power linesrises, the secondary 52 is repulsed so as to be further away from theprimary 48. This maintains the induced voltage in the secondary and thecurrent output therefrom constant. The secondary coil 52 is partlycounter-balanced by a spring 62 so that it is substantially floating,that is there is practically no energy expended in moving or rotatingthe secondary about its axis 58. 'I'his free movement allows foraccurate, automatic coupling and aids in maintaining a constant currentoutput. It is also possible to vary the current output from thetransformer by adjusting this counter-balance.

The ambient temperature compensator hereinbefore described is utilizedto modify the current output of the transformer so that the lthermalsafety switch will always operate or trip within a substantiallyconstant time period. For example, when the ambient temperature is highit is apparent that the tripping device will operate in a shorter timeperiod than when the ambient temperature is low, even though a constantcurrent input is supplied to the heater. This is explained by the factthat the heat output of the heater |82 at any given current input willoperate the tripping device within a certain time period at a settemperature. Lowering the ambient temperature necessarily lengthens thisperiod while higher ambient temperatures correspondingly reduce the timeperiod. of operation. In the present embodiment, therefore, the am- Thusthe radiator |60 modifies perature, is, say 90 degrees F. To'compensatefor such variations the bimetallic coil expands to raise the secondaryand thus lower the current output so that only .45 amp. is beingsupplied to the heater |82, which will cause the solder to fuse withinthe set time period of 90 seconds. 'Ihe foregoing is merely an exampleto illustrate the compensating characteristics of the transformer 20.

It is to be understood that the transformer with its compensatingfeatures and the modified tripping mechanism may be used advantageouslyin connection with one another but their use should not be limited totheir combinationv as either may be used for a specific purpose and willoperate in a very satisfactory manner.

In a like manner the thermal circuit breaker may be advantageouslyapplied to other types of electric control systems that include a devicethat is sensitive to a function of the system for associating thedissipator with the circuit breaker.

While the form of embodiment of the present invention as hereindisclosed constitutes a preferred form, it is to be understood thatother forms might be adapted, all coming within the scope of the claimsas follows:

I claim:

l. In combination with a transformer having two coils movable relativeto one another when said coils are energized, a switching means,electrically operated thermal means for operating said switching means,said thermal means being connected in circuit with one of said coils;and thermal responsive means for controlling the relative movement ofsaid coils for regulating the flow of current through said ilrstmentioned thermal means,

2. A current transformer comprising in combination, a core; a primarywinding associated with the core for inducing a magnetic flux in thecore; a secondary winding associated with the core and subjected yto themagnetic flux in the core for causing a voltage to be induced in thesecondary winding, one of said windings being movable relative to theother and moved in response to changes in the current values in theprimary winding; an electrical translating device energized by thecurrent of the secondary winding; and temperature responsive meansassociated with said movable winding for affecting the movement of saidone winding relative to the other.

3. A current transformer comprising in combination, a core; a primarywinding associated with the core for inducing a magnetic flux in thecore; a. secondary Winding associated with the core and subjected to themagnetic flux in lthe core for causing a voltage to be induced in thesecondary winding, one of said windings being movable relative to theother and moved in response to changes in the current values in theprimary winding; an electrical translating device energized by thecurrent of the secondary winding; and temperature responsive meansassociated with said one winding for tending to increase or decrease theamount of movement of said one winding as the ambient temperaturedecreases and increases respectively.

4. A current transformer comprising in combination, a core; a stationarywinding associated with the core for inducing a magnetic flux in thecore; a movable winding associated with the core and subjected to themagnetic flux in the core for causing a voltage to be induced in thesecondary winding, said movable Winding being repulsed and moved byenergization of the said stationary Winding with a force in direct ratioto the voltage impressed across primary winding of the transformer; anelectrical translating device energized by the secondary winding; meansassociated with the movable winding for yieldingly affecting themovement thereof; and a second means responsive to ambient temperatureconditions for yieldingly affecting the movement of said movablewinding-for increasing and decreasing thel current output of thetransformer substantially as the ambient temperature decreases andincreases respectively.

5. In a switching device, a switch; electrically heated thermal meansfor operating said switch; and means for energizing the said thermalmeans including a second thermal means responsive to ambient temperaturefor increasing and decreasing the current in-put to said first thermalmeans in responseto a decrease and increase respectively of .the ambienttemperature whereby the rst said thermal means operates theswitchingdevice within a substantially constant period regardless of thevariation in the ambient temperature.

ESTEL C. RANEY.

